The invention concerns a cup-shaped housing assembly for a device for separating liquid from air, wherein the cup-shaped housing assembly is designed for receiving at least one filter element that is configured in particular as an annular coalescing element for separation of liquid from air and wherein the cup-shaped housing assembly for closing off its open end face has a housing cover, wherein the housing cover, for discharging the filtered clean air, has at least one clean air opening and wherein the housing cover has at least one raw air inlet for supply of raw air.
The present invention concerns moreover a device for separating liquid from air comprising a cup-shaped housing assembly with a filter element that is designed in particular as an annular coalescing element.
The present invention concerns also a method for mounting a cup-shaped housing assembly on a nipple for detachable connection of the cup-shaped housing assembly with a connecting head that is in particular connected to a compressed air compressor, wherein the cup-shaped housing assembly is detachably connected to the nipple, for example, screwed onto the nipple.
The publication DE 85 01 736.1 U1 discloses a device of the afore mentioned kind and this device is designed for separating oil droplets from air. The filter element or separating element is designed as an annular coalescing element that coalesces the fine oil droplets to larger droplets in the separating element and the larger droplets deposit downstream thereof in downward direction due to the force of gravity. A nipple which is designed as a threaded tubular socket is detachably connectable to a connecting head and a cup-shaped housing assembly in which the filter element is arranged. For discharging the clean air, the connecting head has a central pipe or cylindrical tubular element that projects through the nipple and opens into the filter element. The cylindrical tubular element embodied for separating the separated liquid from the purified air is thus correlated according to the prior art with the connecting head. The cylindrical tubular element extends through the nipple and projects past it. In the known device for separation of oil droplets from air, an annular gap is arranged between the cylindrical tubular element and the nipple for discharging the separated oil. This annular gap is connected with a separate discharge passage.
Moreover, for example, the publications EP 2 108 424 A1, EP 0 806 564 A1, and U.S. Pat. No. 6,972,092 B disclose air/oil separator boxes in which the removal of the separated oil is realized by means of an annular gap in the threaded tubular socket. According to the prior art, the separated oil is thus discharged via an annular gap that is surrounded by the nipple or the tubular socket, i.e., is arranged within the inner diameter of the nipple. This annular gap is formed by providing an additional tubular element that is inserted into the nipple and is arranged between the nipple and the additional tubular element.
The publication DE 88 06 694 U discloses a drain groove that is arranged within the thread of a drain plug. However, this known drain plug does not enable emptying in the completely screwed-in state but requires that the plug must be first unscrewed to some degree for emptying.
The object of the invention is to further develop a cup-shaped housing assembly of the aforementioned kind, a device for separating liquid from air of the aforementioned kind, as well as a method for mounting a cup-shaped housing assembly of the aforementioned kind in such a way that for discharging the filtered clean air as little energy as possible is required.